Nope, neither did the trick (I am attaching a new "bug report log" so you can see that these options have indeed been changed). I do see some new variations of the lockup, to wit:

- The test case to reproduce the crash is that I run Synaptic PM, type in a nonsense search string and while it is searching I grab the window corner and drag it around.

- Prior to disabling the options it would lock up almost immediately.

- Now I've been seeing it lock up and then unfreeze after a few seconds; also saw the X server spontaneously restart (I got the login screen). Repeating the exercise still leads to an unrecoverable crash.